As a typical titanium based MOF, NH₂-MIL-125(Ti) has been widely used as catalyst for photocatalytic CO₂ reduction due to its abundant photoactive sites, large surface area and high porosity. However, the CO₂ conversion efficiency of NH₂-MIL-125(Ti) is still limited due to its weak electron transfer ability. Herein, Zn(II)-porphyrin is selected as photosensitizer to directly coordinate with titanium oxo clusters to endow NH₂-MIL-125(Ti) with a second efficient photoexcitation path to enhance the photocurrent intensity and CO₂ adsorption ability, which realizes 11-fold enhancement in the CO₂/CO conversion efficiency. It is found that the optimized band structure of the dual ligand Ti-based MOFs (D-TiMOF) after the incorporation of Zn(II)-porphyrin contributes a lot for the enhanced photoelectric conversion ability and CO₂ adsorption ability. This research sheds light on designing efficient CO₂/CO conversion MOFs based photocatalyst via porphyrin-metal oxo clusters coordination.

作为典型的钛基MOF，NH ₂ -MIL-125（Ti）由于其丰富的光活性位，大表面积和高孔隙率而被广泛用作光催化还原CO _2的催化剂。然而，由于NH ₂ -MIL-125（Ti）的电子转移能力弱，因此其CO ₂转化效率仍然受到限制。在这里，选择Zn（II）-卟啉作为光敏剂直接与钛氧羰基团配合，为NH ₂ -MIL-125（Ti）提供第二条有效的光激发路径，以增强光电流强度和CO ₂吸附能力，实现了11 CO _2的三倍增强/ CO转换效率。发现掺入Zn（II）-卟啉后的双配体Ti基MOFs（D-TiMOF）的最佳能带结构对增强光电转换能力和CO ₂吸附能力做出了很大贡献。该研究为通过卟啉-金属羰基团簇配合设计基于CO ₂ / CO转化MOFs的高效光催化剂提供了依据。